Secondary batteries have undergone further development, and for example, lithium ion batteries have been receiving attention due to their high capacity, high energy density, and potential for size and weight reduction.
An electrical storage device used as a power source for various electronic and electric devices is generally configured by series-parallel connection of a plurality of secondary batteries. When used as a power source, the electrical storage device is connected to an electronic or electric device and discharges electricity. In the case of charging the electrical storage device, the electrical storage device is connected to a power supply system.
Patent Document 1 is an example of a prior art document relating to lithium ion batteries. Patent Document 2 is an example of a prior art document relating to electrical storage devices.
A lithium ion battery according to Patent Document 1 is capable of preventing overcharging/overdischarging and controlling battery temperature without retaining space for heat dissipation. An electrical storage device according to Patent Document 2 is capable of quick charging with high current and thereby reliably cutting the charging current off when the battery temperature becomes high.